Problem: What do the following two equations represent? $5x-5y = -4$ $5x-5y = -4$
Solution: Putting the first equation in $y = mx + b$ form gives: $5x-5y = -4$ $-5y = -5x-4$ $y = 1x + \dfrac{4}{5}$ Putting the second equation in $y = mx + b$ form gives: $5x-5y = -4$ $-5y = -5x-4$ $y = 1x + \dfrac{4}{5}$ The above equations turn into the same equation, so they represent equal lines.